FBI concerns, GOP spats and Rand Paul's talkathon leave domestic surveillance program in doubt

The fate of the government's bulk collection of Americans' phone records is unclear following an FBI warning, House-Senate disagreements and more than 10 hours of criticisms by a GOP presidential candidate.

Sen. Rand Paul of Kentucky dominated the Senate floor from 1:18 p.m. to 11:49 p.m. Wednesday to decry the National Security Agency's mass collection of phone data without warrants. He highlighted deep divisions within Congress over the program whose existence was exposed by former contractor Edward Snowden.

Paul's campaign issued a fundraising appeal while he slowly paced and steadily talked in a mostly empty Senate chamber.

Paul opposes renewal of key sections of the Patriot Act, set to expire June 1. The government cites them to authorize the massive examination of who calls who on American phones.